public void RightNestedComponentsAreInlined()
{
// x*(y*z) = x*y*z
var innerComponent = new DualFactorComponent(new AlphabeticFactor("y"), new AlphabeticFactor("z"), true);
var outerComponent = new DualFactorComponent(new AlphabeticFactor("x"), Factorizer.ToFactor(innerComponent), true);
var componentList = new ComponentList(outerComponent);
Assert.AreEqual(3, componentList.Factors.Count);
Assert.IsTrue(componentList.Factors[0].Factor is AlphabeticFactor);
Assert.IsTrue(componentList.Factors[0].IsInNumerator);
Assert.IsTrue(componentList.Factors[1].Factor is AlphabeticFactor);
Assert.IsTrue(componentList.Factors[1].IsInNumerator);
Assert.IsTrue(componentList.Factors[2].Factor is AlphabeticFactor);
Assert.IsTrue(componentList.Factors[2].IsInNumerator);
Assert.AreEqual("x*y*z", componentList.ToString());
}
public void DoubleNestedComponentsAreInlined()
{
// (w*x)*(y*z) = w*x*y*z
var leftInnerComponent = new DualFactorComponent(new AlphabeticFactor("w"), new AlphabeticFactor("x"), true);
var rightInnerComponent = new DualFactorComponent(new AlphabeticFactor("y"), new AlphabeticFactor("z"), true);
var outerComponent = new DualFactorComponent(Factorizer.ToFactor(leftInnerComponent), Factorizer.ToFactor(rightInnerComponent), true);
var componentList = new ComponentList(outerComponent);
Assert.AreEqual(4, componentList.Factors.Count);
Assert.IsTrue(componentList.Factors[0].Factor is AlphabeticFactor);
Assert.IsTrue(componentList.Factors[0].IsInNumerator);
Assert.IsTrue(componentList.Factors[1].Factor is AlphabeticFactor);
Assert.IsTrue(componentList.Factors[1].IsInNumerator);
Assert.IsTrue(componentList.Factors[2].Factor is AlphabeticFactor);
Assert.IsTrue(componentList.Factors[2].IsInNumerator);
Assert.IsTrue(componentList.Factors[3].Factor is AlphabeticFactor);
Assert.IsTrue(componentList.Factors[3].IsInNumerator);
Assert.AreEqual("w*x*y*z", componentList.ToString());
}
private static Expression ToExpression(ComponentList componentList)
{
if (componentList.Factors.Count == 1)
{
if (componentList.Factors[0].IsInNumerator)
{
return ToExpression(componentList.Factors[0].Factor);
}
if (componentList.Factors[0].Factor is NumericFactor && !componentList.Factors[0].IsInNumerator)
{
var nf = (NumericFactor)componentList.Factors[0].Factor;
if (nf.Number is Integer)
{
return new SingleComponentExpression(new IntegerFraction(new Integer(1), (Integer)nf.Number));
}
}
}
return new SingleComponentExpression(componentList);
}
protected override Expression InnerEvaluate(params Expression[] parameters)
{
var parameter = parameters[0].Evaluate();
var numericFactor = Factorizer.ToFactor(parameter) as NumericFactor;
if (numericFactor == null)
{
return parameter;
}
if (numericFactor.Number.IsZero)
{
return Expressionizer.ToExpression(numericFactor);
}
if (numericFactor.Number.IsOne)
{
return Expressionizer.ToExpression(new NumericFactor(new Integer(1)));
}
var number = Math.Abs(numericFactor.Number.ValueAsFloat());
// TODO: If number is fractional and greater than 1,
// convert to an integer fraction and go from there.
if (number > 1 && number % 1 > 0)
{
return Expressionizer.ToExpression(numericFactor);
}
var isFractional = false;
if (number > 0 && number < 1)
{
number = 1 / number;
isFractional = true;
}
var primeCounts = Factorize(number);
var useFloats = numericFactor.Number is Float;
var unevaluatedExponentFunctions = primeCounts.Select(pc => pc.Value > 1
? new FunctionComponent(new Exponent(), new List<Expression>
{
Expressionizer.ToExpression(new NumericFactor(useFloats ? (Number)new Float(pc.Key) : new Integer(pc.Key))),
Expressionizer.ToExpression(new NumericFactor(new Integer(pc.Value)))
})
: Componentizer.ToComponent(new NumericFactor(useFloats ? (Number)new Float(pc.Key) : new Integer(pc.Key))));
var componentList = new ComponentList(unevaluatedExponentFunctions.Select(uef => new ComponentListFactor(Factorizer.ToFactor(uef))).ToList());
if (isFractional)
{
foreach (var componentListFactor in componentList.Factors)
{
componentListFactor.IsInNumerator = false;
}
if (!numericFactor.Number.IsNegative)
{
componentList.Factors.Insert(0, new ComponentListFactor(new NumericFactor(new Integer(1))));
}
}
if (numericFactor.Number.IsNegative)
{
componentList.Factors.Insert(0, new ComponentListFactor(new NumericFactor(useFloats
? (Number)new Float(-1)
: new Integer(-1))));
}
return Expressionizer.ToExpression(componentList);
}
